Exogenous ochronosis in ethnic Chinese Asians: a clinicopathological study, diagnosis and treatment

Abstract

Exogenous ochronosis is believed to be an uncommon complication of treatment with hydroquinone- containing skin-lightning agents. It is widely believed that the condition is found almost exclusively in dark-skinned individuals and uncommon in other skin-types. To show that exogenous ochronosis may be present in ethnic Chinese Asians. Facial skin biopsies were obtained from suspicious lesions in ethnic Chinese patients presenting at a private dermatology clinic. Clinical photographs, ultraviolet (UV) photographs and digital dermatoscopic pictures were also obtained. 15 patients of ethnic Chinese origin had histologically-confirmed exogenous ochronosis. The difficulties in differentiating exogenous ochronosis from melasma are discussed and there is a likelihood of under-reporting as the clinical presentation of the condition may be misleading. Exogenous ochronosis may exist amongst ethnic Chinese patients with fairer skin-types, contrary to the commonly-accepted perception that it is more prevalent in darker skin-types.